CVE-2024-26685

nilfs2: fix potential bug in end_buffer_async_write

Published Apr 3, 2024 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

nilfs2: fix potential bug in end_buffer_async_write

According to a syzbot report, end_buffer_async_write(), which handles the
completion of block device writes, may detect abnormal condition of the
buffer async_write flag and cause a BUG_ON failure when using nilfs2.

Nilfs2 itself does not use end_buffer_async_write(). But, the async_write
flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue
with race condition of competition between segments for dirty blocks") as
a means of resolving double list insertion of dirty blocks in
nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the
resulting crash.

This modification is safe as long as it is used for file data and b-tree
node blocks where the page caches are independent. However, it was
irrelevant and redundant to also introduce async_write for segment summary
and super root blocks that share buffers with the backing device. This
led to the possibility that the BUG_ON check in end_buffer_async_write
would fail as described above, if independent writebacks of the backing
device occurred in parallel.

The use of async_write for segment summary buffers has already been
removed in a previous change.

Fix this issue by removing the manipulation of the async_write flag for
the remaining super root block buffer.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-3840-1 linux security update
Debian DLA Debian DLA DLA-3842-1 linux-5.10 security update
Debian DSA Debian DSA DSA-5658-1 linux security update
Debian DSA Debian DSA DSA-5681-1 linux security update
Ubuntu USN Ubuntu USN USN-6766-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6766-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6766-3 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-6767-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6767-2 Linux kernel (BlueField) vulnerabilities
Ubuntu USN Ubuntu USN USN-6795-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-6828-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6895-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6900-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7332-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7332-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7332-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7342-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7344-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7344-2 Linux kernel vulnerabilities
History
Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
Linux
Linux linux Kernel
Weaknesses CWE-787
CPEs cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux
Linux
Linux linux Kernel
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 23, 2026, 3:36 PM
Reserved
Feb 19, 2024, 2:20 PM
Status
Analyzed
Published
Apr 3, 2024, 3:15 PM
Modified
Jun 17, 2026, 7:18 AM
Severity
Low
Public date
Apr 3, 2024, 12:00 AM